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Dibenzofuran (DBF) is converted to a vacuum-sublimable, electron-transporting host material via 2,8-substitution with diphenylphosphine oxide moieties. Close pi-pi stacking and the inductive influence of P=O moieties impart favorable electron-transport properties without lowering the triplet energy. A maximum external quantum efficiency of 10.1% and luminance power efficiency of 25.9 lm/W are realized using this material as the host for the blue-green electrophosphorescent molecule, iridium(III) bis(4,6-(di-fluorophenyl)pyridinato-N,C(2')picolinate (FIrpic).

Background/purpose: Vascular tumors and malformations are rare. This large series describes vascular anomalies of the female genitalia and their management., Methods: An international review board-approved retrospective database and a record review from 1994 through 2004 was conducted., Results: Of the 3186 female patients with a vascular anomaly, 82 (2.6%) had a lesion in the external genitalia. There were 60 malformations and 22 tumors. The most common malformations were combined capillary-lymphaticovenous, venous, and lymphatic. Tumors included 20 infantile hemangiomas, 1 kaposiform hemangioendothelioma, and 1 kaposiform lymphangioendothelioma. The referring diagnosis was incorrect in 56% of patients. Cutaneous stains, swelling, deformity, bleeding, fluid leakage, or infection were the prominent symptoms. Magnetic resonance imaging, ultrasonography, angiography, and computed tomography were used for diagnostic clarification. Malformation treatment consisted of sclerotherapy, embolization, and operative resection. Tumor management included observation, surgical excision, and antiangiogenic pharmacotherapy., Conclusions: Vascular anomalies of the female external genitalia are uncommon, and the initial diagnosis is often inaccurate. Correct diagnosis using clinical and radiographic data is feasible and leads to meaningful intervention for these frequently devastating lesions. Whereas tumors may respond to excision or antiangiogenic drugs, malformations require ablation or resection. Evaluation and management of these lesions is complex and benefits from interdisciplinary care.

Background: The extracellular dynamics after intravascular sclerotherapy with an injectable, fibroblast-based engineered construct is unknown., Methods: Rabbits underwent ethanol sclerotherapy of a jugular vein segment. Control animals (n = 40) underwent no further treatment or an acellular collagen hydrogel was injected. Experimental animals (n = 20) received a tissue-engineered construct. After 1, 2, 4, and 20 to 24 weeks, segments were evaluated for collagen, glycosaminoglycan (GAG), matrix metalloproteinase (MMP) 2 and 9, and tissue inhibitors of MMP (TIMPs) 1 and 2 and scored on a scale of 0 to 3. Groups and time points were compared using nonparametric statistical analysis., Results: Collagen content was higher in animals that received fibroblasts (P < .05). Glycosaminoglycan analysis showed a higher grade only at 1 week (P < .05). Collagen and GAG deposition were prominent at weeks 1 through 4, and decreased over time. Both MMP-2 and MMP-9 and TIMP-1 and TIMP-2 grade decreased with time (P < .01) in all groups, with no differences between groups., Conclusion: Enhancement of intravascular sclerotherapy by tissue engineering stems, at least in part, from increased local deposition of collagen and GAG. MMP and TIMPs may play a role in recanalization after experimental sclerotherapy. Tissue engineering may be a valuable adjunct for the treatment of vascular malformations.

Purpose: To retrospectively identify factors associated with an increased risk of adverse cardiovascular or respiratory events during sedation of pediatric patients for imaging examinations., Materials and Methods: This HIPAA-compliant study was institutional review board approved; the requirement for informed consent was waived. All sedation information--including patient demographics, medications (doses and routes of administration), time required to sedate and before discharge, American Society of Anesthesiologists physical status classification, adverse events, and failed sedations--was maintained in a computerized database. A review of the data on all patients sedated between 1997 and 2003 for magnetic resonance imaging, computed tomography, and interventional radiology revealed associated adverse respiratory events in 70 patients. Adverse respiratory event was defined as oxygen desaturation of at least 5%, pulmonary aspiration, and need for airway resuscitation. Adverse cardiovascular events were defined as cardiac arrest and hemodynamic changes requiring medical therapy. Adverse events were compared between sedation regimens--which included fentanyl, chloral hydrate, pentobarbital, and midazolam hydrochloride--by using the Fisher exact test. Multiple logistic regression analysis was applied to identify potential predictors of adverse events., Results: Among 16,467 sedations performed, 70 (0.4%) were associated with adverse respiratory events: 58 cases of oxygen desaturation, two pulmonary aspirations, 10 cases of airway resuscitation, and no cardiovascular events. Nearly 30% (n = 20) of the 70 patients who had an adverse event had a history of serious respiratory illness. Logistic regression analysis revealed that neither patient age, weight, or sex nor type of imaging procedure was associated with an increased risk of an adverse event. Use of a single sedation agent was associated with lower adverse event risk than was use of multiple agents (P < .001)., Conclusion: Consideration should be given to using single agents, avoiding the use of multidrug sedation regimens, and recognizing that a history of pulmonary disease could be associated with an increased risk of adverse respiratory events despite a currently stable respiratory state., (RSNA, 2005)

We describe 10 children with multiple vascular lesions of the skin and gastrointestinal tract associated with sustained, minor thrombocytopenia. In some children, there was involvement of the lung (n = 5), bone (n = 2), liver (n = 1), spleen (n = 1), and muscle (n = 1). The cutaneous lesions were congenital, multifocal, discrete, red-brown and variably blue macules and papules; in 3 children, a large dominant plaque was also present. All children developed hematemesis and/or melena and endoscopic evaluation revealed several to numerous small mucosal lesions that involved all levels of the gastrointestinal tract. Three of 5 children with pulmonary nodules had cough and 1 also had hemoptysis. Biopsies of cutaneous, gastrointestinal, and pulmonary lesions showed thin-walled, blood-filled vascular channels and variable endothelial hyperplasia. The endothelial nuclei were elongated, round, crescentic, or hobnailed. Cytoplasmic and extracellular periodic acid-Schiff positive deposits were often present in the zones of endothelial hyperplasia. The platelets were small in some children, suggesting a primary defect, possibly accounting for the thrombocytopenia. Gastrointestinal hemorrhage and hemoptysis required antiangiogenic therapy. The constellation of findings defines a congenital proliferative disorder of blood vessels with a distinctive microscopic appearance. We have termed this relatively indolent or slowly progressive disorder cutaneovisceral angiomatosis with thrombocytopenia because this designation incorporates its major clinical and histopathologic features.

Objective: Matrix metalloproteinases (MMPs) and the angiogenic proteins basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) have been implicated in mechanisms of human cancer and metastasis. Assays were conducted on the urine of patients with vascular anomalies (tumors and malformations), relatively common and occasionally life-threatening disorders for which few therapies exist. We sought to determine whether these angiogenesis modulators are present in the urine and whether their expression is associated with the extent and clinical course of the vascular lesion., Methods: A total of 217 patients with vascular anomalies and 74 age-matched control subjects participated. Urinary MMP expression was determined by substrate gel electrophoresis. Urinary bFGF and VEGF levels were measured by enzyme-linked immunosorbent assay. Each patient was assigned to 1 of 2 categories (tumor or malformation) and 1 of 9 specific groups. Extent of the vascular lesion and activity were scored by a blinded clinician., Results: Urinary high molecular weight (hMW) MMPs and bFGF were significantly increased in patients with vascular tumors (53%) and vascular malformations (41%), compared with control subjects (22%). These percentages increased as a function of extent of the lesion and disease activity. hMW MMPs were increased in 4 groups: infantile hemangioma, other vascular neoplasms, lymphatic malformation and capillary-lymphaticovenous malformations, and extensive and unremitting capillary malformation and arteriovenous malformation. No significant differences among the groups were detected for low molecular weight MMPs or VEGF., Conclusions: Expression patterns of hMW MMPs and bFGF in the urine of patients with tumors and malformations are consistent with their different clinical behavior. These data represent the first evidence that MMPs are elevated in the urine of children with vascular anomalies. These data also suggest that the increased expression of urinary MMPs parallels the extent and activity of vascular anomalies in children. In addition to tumors, vascular malformations are angiogenesis dependent, suggesting that progression of a vascular malformation might be suppressed by angiogenic inhibitors, which would target bFGF and MMPs.

Cutis marmorata telangiectatica congenita (CMTC) is a rare congenital disorder. We describe an 8-year-old boy with CMTC who presented with symptomatic claudication and diminished distal pulses. Imaging showed severe stenosis of the right common iliac artery, and the child underwent uncomplicated ilio-iliac bypass using prosthetic graft. This is the first report of a patient with CMTC and major vessel stenosis, successfully treated with a prosthetic graft bypass.

Background: Lymphatic malformation of the tongue and floor of the mouth is associated with chronic airway problems, recurrent infection, and functional issues related to speech, oral hygiene, and malocclusion. There are no accepted anatomic guidelines or treatment protocols., Methods: This retrospective review focused on anatomic extent, treatment, complications, and airway management in 31 patients with lymphatic malformation of the lingual base and oral floor., Results: Involved adjacent structures included the neck (77 percent), mandible (41 percent), face (42 percent), lips (10 percent), pharynx (45 percent), and larynx (26 percent). Fifty-eight percent of patients required tracheostomy during infancy; decannulation was possible in two-thirds of these patients. Management included resection alone (42 percent), resection and sclerotherapy (26 percent), resection and laser coagulation (16 percent), sclerotherapy and laser coagulation (16 percent), and resection and radiofrequency ablation (3 percent). Resection involved the neck (58 percent), floor of the mouth (52 percent), and tongue (42 percent); there were often multiple procedures. Aspiration was tried with little success in 10 percent of patients. Virtually all patients had residual abnormal lymphatic tissue. Complications and posttherapeutic problems included infection (81 percent), neural damage (27 percent), difficulty in speech (23 percent), feeding problems (10 percent), and seroma or hematoma (6 percent). Associated dental/orthognathic conditions, particularly prognathism and anterior open bite, were documented in one-third of patients., Conclusions: The initial step in the protocol is control of the neonatal airway. Staged cervical resection is undertaken in late infancy to early childhood; resection should also include abnormal tissue in the oral floor. Sclerotherapy is primarily for macrocystic disease or secondarily for recurrent cysts following partial extirpation. Vesicles of the mucous membranes and dorsal tongue are treated either by sclerotherapy, laser (carbon dioxide, yttrium-aluminum-garnet, or potassium-titanyl-phosphate), or radiofrequency ablation. Reduction for macroglossia is indicated for persistent protrusion or to allow correction of malocclusion. Embolization controls lingual bleeding. Orthognathic procedures are undertaken at the appropriate age, only after lingual size and position are acceptable.

Background/purpose: Sclerotherapy for vascular malformations is often limited by luminal recanalization. This study examined whether an injectable tissue-engineered construct could prevent this complication in a rabbit model of venous sclerotherapy., Methods: Ethanol sclerotherapy of a temporarily occluded jugular vein segment was performed in 46 rabbits, which were then divided into 3 groups. Group I (n = 16) had no further manipulations. In groups II (n = 15) and III (n = 15), 0.5 mL collagen hydrogel was injected intraluminally, respectively, devoid of and seeded with autologous fibroblasts. At 1, 4, and 20 to 24 weeks postoperatively, vein segments were examined for patency and resected for histological evaluation. Statistical analysis was by Fisher's Exact test., Results: All vein segments were occluded at 1 and 4 weeks in all groups, despite histological evidence of progressive endothelial ingrowth. However, at 20 to 24 weeks, angiography demonstrated restoration of vessel patency in groups I (3/6) and II (3/5), but not in group III (0/6; P = .043), in which histology confirmed an obliterated lumen for all vessels., Conclusion: An injectable, fibroblast-based, engineered construct prevents midterm to long-term recanalization in a leporine model of vascular sclerotherapy. This novel therapeutic approach may prevent recurrence of vascular malformations after sclerotherapy, thus reducing the need for repeated procedures and morbid operative resections.

Kasabach-Merritt phenomenon is a serious coagulopathy associated with kaposiform hemangioendothelioma (KHE), tufted angioma, and possibly other vascular neoplasms. KHE presenting in the absence of Kasabach-Merritt phenomenon is rare, although tufted angioma frequently occurs without thrombocytopenia. We retrospectively reviewed 10 cases of KHE without Kasabach-Merritt phenomenon. The tumors appeared as soft tissue masses with the overlying skin being either normal, erythematous, or violaceous. There were no radiologic or microscopic differences in noncoagulopathic KHE as compared with coagulopathic KHE. Evidence of platelet trapping and hemosiderin deposition was seen histologically, despite normal serum platelet levels. All KHE were less than 8 cm in diameter, suggesting that tumors that grow no larger than this size are less likely to trap platelets in sufficient quantity to cause thrombocytopenia. Our series confirms that KHE appears with a wide spectrum of behavior and response to treatment. The decision as to whether or not to treat a noncoagulopathic KHE should be based on the size and location of the tumor and the possible side effects of therapy.

Background: The external ear is the second most common site for extracranial arteriovenous malformation in the head and neck., Methods: This retrospective review of 41 patients with auricular arteriovenous malformation was based on medical records, imaging studies, and photographs. Data were collected on natural history, progression, and outcome; patients were questioned about quality of life after treatment., Results: The median age at initial presentation was 26 years (range, 1 to 55 years), and Schobinger stage was I in two patients, II in 19 patients, and III in 20 patients. No patients had a Schobinger stage of IV. Expansion occurred during childhood in seven patients, adolescence in 14 patients, pregnancy in 10 patients, and adulthood in 10 patients. Distribution of auricular and extra-auricular arteriovenous malformation was not limited to "watershed" areas between vascular territories (angiosomes). Twelve patients were untreated (follow-up, 0.5 to 6 years). Mean follow-up time for the 29 treated patients was 5.19 years (range, 1 to 18.75 years). Proximal ligation in nine patients caused progression: eight of them underwent amputation and one had embolization. Fifteen patients had embolization only: the arteriovenous malformation worsened and amputation was necessary in six patients; in the remaining nine patients, two improved, four persisted, and three worsened. Of 20 patients who had auricular amputation, 16 (80 percent) were controlled, three (15 percent) improved, and one had unresectable, residual cervicofacial arteriovenous malformation. Of 22 of 29 treated patients surveyed, 81 percent were satisfied with their management. Hearing was either unaffected (n = 15) or diminished (n = 5); two patients noted decreased sound localization., Conclusions: The authors recommend periodic evaluation for stage I to II auricular arteriovenous malformation and intervention if there is evolution to stage III. Preoperative embolization and partial or total amputation effectively control auricular and para-auricular arteriovenous malformation. Embolization can be palliative in children or in patients who are not psychologically prepared for amputation. Extensive extra-auricular arteriovenous malformation requires individualized endovascular therapy and resection.

Objective: We report the largest clinical experience to date of surgically treated patients with blue rubber bleb nevus syndrome (BRBNS)., Summary Background Data: BRBNS is a rare congenital disorder presenting with multifocal venous malformations of the skin, soft tissues, and gastrointestinal (GI) tract. Patients with BRBNS develop anemia from chronic GI bleeding, and require lifelong treatment with iron and blood transfusions. An aggressive surgical approach to treat the GI venous malformations of BRBNS has been considered unlikely to be successful because of the large number of lesions, their position throughout the GI tract, and the likelihood of recurrence. Based on our belief that eradicated lesions would not recur, we undertook the removal of all GI tract lesions in an effort to eliminate bleeding., Methods: Ten patients with BRBNS were treated from 1993 to 2002. Lesions were identified using complete GI endoscopy. The multiple venous malformations were removed by a combination of wedge resection, polypectomy, suture-ligation, segmental bowel resection, and band ligation., Results: Patient ages ranged from 2 to 36 years, and patients received an average of 53 prior blood transfusions. A mean of 137 focal GI venous malformations per patient were resected at operation (range 4-557), with a mean operative duration of 14 hours (range 7-23 hours). Only 1 patient who had a less extensive procedure developed recurrent GI bleeding. The mean follow-up period was 5.0 years (range 2.9-10.3 years)., Conclusions: We believe that an aggressive excisional approach is indicated for the venous anomalies that cause GI bleeding in BRBNS.

Background/purpose: Treatment of vascular malformations with sclerotherapy is often complicated by reexpansion secondary to endothelial recanalization. This study examined the use of an autologous fibroblast construct to enhance intraluminal scar formation after sclerotherapy., Methods: New Zealand rabbits (n = 15) underwent ethanol sclerotherapy of a segment of the facial vein. After intraluminal saline flush, animals were equally divided into 3 groups. In group I, no further manipulations were performed. In groups II and III, collagen hydrogel was injected into the sclerosed vein, respectively, without and seeded with autologous green fluorescent protein-labeled fibroblasts. One week postoperatively, the vein segments were examined for patency and resected for histology., Results: The sclerosed vein segments remained occluded in all animals. Histological examination of luminal thrombi demonstrated numerous viable fibroblasts in group III, whereas there were none in the control specimens from groups I and II. The presence of the injected autologous green fluorescent protein-labeled fibroblasts within thrombi of group III was confirmed by immunohistochemistry., Conclusions: An injectable tissue-engineered construct enhances sclerotherapy of the jugular vein in a leporine model by reliably delivering fibroblasts that populate the resultant thrombus. Further analysis of this novel therapeutic concept as a means to augment permanent scar formation and reduce luminal recanalization is warranted.

Lymphatic malformation in the orbital cavity and surrounding region often causes disfigurement and visual problems. To better clarify the evolution and treatment of this condition, the authors studied a retrospective cohort of 42 consecutive patients seen between 1971 and 2003 and analyzed anatomic features, complications, and management. The ratio of female to male patients was 1:1. Most periorbital lymphatic malformations were noted at birth (59 percent), presenting as either unilateral swelling (60 percent) or a periorbital mass (24 percent). Sixty-two percent of lesions were on the left side. The ipsilateral cheek, temple, and forehead also were involved in 57 percent of patients. Twenty-two percent of lesions were intraconal, 30 percent were extraconal, and 48 percent were in both spaces. Forty-five percent of children had an associated cerebral developmental venous anomaly. Periorbital lymphatic malformation caused major morbidity; 52 percent of patients had intralesional bleeding and 26 percent of patients had a history of infection. Other common complications included intermittent swelling (76 percent), blepharoptosis (52 percent), proptosis (45 percent), pain (21 percent), amblyopia (33 percent), chemosis (19 percent), astigmatism (17 percent), and strabismus (7 percent). Ultimately, 40 percent of children had diminished vision and 7 percent became blind in the affected eye. Management of periorbital lymphatic malformation involved an interdisciplinary team that included an interventional radiologist, a craniofacial surgeon, and an ophthalmologist. The two therapeutic strategies were sclerotherapy (40 percent) and resection (57 percent); most patients required several interventions. A coronal approach was used for subtotal excision of fronto-temporal-orbital lymphatic malformation in 13 patients, whereas a tarsal incision was used for lesions isolated to the eyelid (n = 14). Ocular proptosis was temporarily managed by tarsorrhaphy (n = 9), but expansion of the bony orbit was needed to correct persistent proptosis (n = 8). Orbital exenteration was necessary in two patients.

Purpose: To compare the effectiveness and safety of oral (PO) versus intravenous (IV) pentobarbital sedation for magnetic resonance (MR) imaging and computed tomography (CT) in infants younger than 12 months., Materials and Methods: The institutional review board approved the review of medical records and determined informed consent to be unnecessary. All parents gave informed consent for patient sedation. Prior to MR imaging or CT, infants younger than 12 months were sedated with PO pentobarbital (4-8 mg per kilogram body weight) or IV pentobarbital (2-6 mg/kg), depending on the presence of an IV catheter or need for IV contrast medium. A computer database used to record sedation data was reviewed for data from January 1997 to September 2003. PO and IV sedation groups were compared for mean age, weight, dose, time to sedation, time to discharge, and duration of sedation with a two-sample Student t test. Multivariate analysis of covariance was used to determine whether differences in sedation time, time to discharge, and duration of sedation between groups were independent of age, weight, sex, American Society of Anesthesiologists physical status classification, dose, and type of procedure. Sedation effectiveness (outcome) was determined as the percentage of sedation failures in each group. Safety was determined separately for other adverse events as a total and for respiratory adverse events., Results: A total of 2164 infants received 2419 (1264 PO, 1155 IV) doses of pentobarbital for sedation. Weight and sex were comparable between groups. Time to sedation was significantly longer with PO than with IV pentobarbital (18 minutes +/- 11 vs 7 minutes +/- 7; P < .01), but time to discharge was similar, at approximately 108 minutes +/- 35. Total adverse events rate during sedation was not significantly different (0.8% [PO] vs 1.3% [IV]), but incidence of abnormal oxygen saturation (5% decrease from baseline, >1 minute duration) differed significantly (0.2% [PO] vs 0.9% [IV]; P = .02). Sedation effectiveness was comparable (failure rate, 0.5% [PO] vs 0.3% [IV]; P = .76)., Conclusion: PO pentobarbital has comparable effectiveness and a lower rate of respiratory complications compared with IV pentobarbital in infants younger than 12 months; its use should be considered, regardless of presence of an IV catheter., ((c) RSNA, 2004.)

Birthmarks are common and commonly ignored by patients and primary care doctors. Yet they sometimes represent significant vascular anomalies that require diagnosis and treatment. We summarize when and how to work up a variety of vascular anomalies.

Low flow vascular malformations, especially venous and macrocystic lymphatic malformations, are effectively treated by percutaneous intralesional injection of sclerosant drugs, such as ethanol and detergent sclerosant drugs. Good to excellent results are possible in 75%-90% of patients who undergo serial sclerotherapy. Most adverse effects are manageable, but severe complications can result from the intravascular administration of ethanol. It is generally recommended that the treatment of vascular malformations be performed in a multidisciplinary setting by practitioners with appropriate training and support.

Background: Children with hemihypertrophy are screened for Wilms tumor, because this condition is a risk factor for developing the neoplasm. Patients with Klippel-Trenaunay syndrome (KTS) are often considered potential candidates for Wilms tumor, because they have unilateral overgrowth of the lower limb. In our experience, however, an association between KTS and Wilms tumor has not been observed., Methods: To determine whether KTS and Wilms tumor are associated, we reviewed our institutional experience for patients with both diagnoses and searched the Klippel-Trenaunay literature for patients with Wilms tumor. The National Wilms Tumor Study Group database also was studied to identify patients with KTS. Two-sided exact binomial tests were used to evaluate whether patients with 1 condition had an increased risk for the other. Ninety-five percent confidence intervals for these 2 risks were compared with the general population risks of Wilms tumor (1 in 10 000) and KTS (1 in 47 313)., Results: None of the 115 patients with KTS followed at our institution developed Wilms tumor. One case of Wilms tumor has been reported in 1363 patients with KTS in the literature, giving a confidence interval of (1/57 377) and (1/267). None of the 8614 patients in the National Wilms Tumor Study Group database had KTS, giving a confidence interval of (0, 1/2336). Because the risks of KTS and Wilms tumor in the population fall within these confidence intervals, one cannot conclude that the risks of KTS among Wilms tumor patients or Wilms tumor among KTS patients are any different from the corresponding risks in the general population., Conclusions: Patients with KTS are not at increased risk for developing Wilms tumor and thus should not undergo routine ultrasonographic screening.

Objective: This study was undertaken to determine different imaging patterns in infantile hepatic hemangiomas and to explore the relationship between clinical presentations, imaging findings, and response to therapy., Materials and Methods: The imaging studies and clinical records of all patients with infantile hepatic hemangiomas from two tertiary children's hospitals were reviewed. Univariate and multivariate stepwise logistic regression techniques were used to determine whether clinical presentation and imaging variables differentiated the type of treatment required., Results: Typical hemangiomas appeared as focal or multifocal T2-hyperintense spheres with centripetal contrast enhancement and dilated feeding and draining vessels. Three atypical patterns included focal mass lesions with central varix with or without direct shunts, focal mass with central necrosis or thrombosis, and massive hemangiomatous involvement of the liver with abdominal vascular compression. In general, patients with focal lesions without high flow needed no treatment, and those with central varix and direct shunts developed severe high-output cardiac failure that responded quickly to embolization. The pattern of massive replacement of liver was associated with hypothyroidism, abdominal compartment syndrome, and a high mortality rate. Multivariate analysis of 55 patients indicated that congestive heart failure was the only independent predictor of treatment (p = 0.005). The presence of a shunt was the only independent factor associated with embolization or surgery (p = 0.002)., Conclusion: Although the imaging features of infantile hepatic hemangiomas vary to some extent, MRI features are typical in most patients and certain imaging findings are predictive of the clinical course. MRI is the technique of choice in diagnosing infantile hepatic masses.

Purpose: To compare the effectiveness and safety of oral pentobarbital and oral chloral hydrate for sedation in infants younger than 1 year during magnetic resonance (MR) imaging and computed tomography (CT)., Materials and Methods: A computerized database was used to collect information about all cases in which sedation was used. Outcomes of all infants who received oral pentobarbital or oral chloral hydrate for sedation between 1997 and 2002 were reviewed. Two study groups were compared for sedation and discharge times by using Student t test and for adverse events by using Fisher exact test and multiple logistic regression analysis., Results: Infants (n = 1,316) received an oral medication for sedation. Mean doses were 50 mg/kg chloral hydrate and 4 mg/kg pentobarbital. Student t test demonstrated no difference in mean time to sedation and in time to discharge between groups. Overall adverse event rate during sedation was lower with pentobarbital (0.5%) than with chloral hydrate (2.7%) (P <.001). There were fewer episodes of oxygen desaturation with pentobarbital (0.2%) than with chloral hydrate (1.6%) (P <.01). Both medications were equally effective in providing successful sedation., Conclusion: Although oral pentobarbital and oral chloral hydrate are equally effective, the incidence of adverse events with pentobarbital was significantly reduced., (Copyright RSNA, 2003)

Objective: IV pentobarbital is used in radiology departments for sedating pediatric patients undergoing diagnostic imaging. To our knowledge, no published studies have documented end-tidal carbon dioxide levels during sedation with IV pentobarbital. The purpose of this prospective study was to determine the effects of different doses of IV pentobarbital with or without fentanyl on end-tidal carbon dioxide levels during deep sedation of pediatric patients undergoing MRI., Subjects and Methods: One hundred sixty-five patients (70 girls, 95 boys) having a mean age of 3.4 years received IV pentobarbital sedation with or without fentanyl for undergoing MRI from January through March 2002. Each child was sedated with 2-6 mg/kg of body weight of IV pentobarbital and an additional 1-3 micro g/kg of fentanyl if needed. After the administration of sedation, a 28-ft (8.5 m) nasal cannula with capnography capability was applied to each patient, and capnogram tracings and values were recorded every 5 min., Results: Mean values of end-tidal carbon dioxide were between 37 and 42 mm Hg during 60 min of sedation for both groups. When IV pentobarbital was used alone, no significant difference was seen between patients who received 3-5 mg of pentobarbital and those who received more than 5 mg (p = 0.97, F test)., Conclusion: End-tidal carbon dioxide levels remain within normal clinical range during sedation with IV pentobarbital with or without fentanyl. Our sedation protocol produced no significant deviations from normal respiratory parameters.

Capillary malformation (CM), or "port-wine stain," is a common cutaneous vascular anomaly that initially appears as a red macular stain that darkens over years. CM also occurs in several combined vascular anomalies that exhibit hypertrophy, such as Sturge-Weber syndrome, Klippel-Trenaunay syndrome, and Parkes Weber syndrome. Occasional familial segregation of CM suggests that there is genetic susceptibility, underscored by the identification of a large locus, CMC1, on chromosome 5q. We used genetic fine mapping with polymorphic markers to reduce the size of the CMC1 locus. A positional candidate gene, RASA1, encoding p120-RasGAP, was screened for mutations in 17 families. Heterozygous inactivating RASA1 mutations were detected in six families manifesting atypical CMs that were multiple, small, round to oval in shape, and pinkish red in color. In addition to CM, either arteriovenous malformation, arteriovenous fistula, or Parkes Weber syndrome was documented in all the families with a mutation. We named this newly identified association caused by RASA1 mutations "CM-AVM," for capillary malformation-arteriovenous malformation. The phenotypic variability can be explained by the involvement of p120-RasGAP in signaling for various growth factor receptors that control proliferation, migration, and survival of several cell types, including vascular endothelial cells.

Varicocele is a very common condition. Although some patients may have pain, it is usually asymptomatic. Treatment of adolescent and pediatric patients is based on the desire to prevent testicular dysfunction and infertility that may be irreversible in adulthood. Venous embolization of the spermatic vein is an effective and minimally invasive method to occlude the varicocele and is known to improve testicular size and function. Embolization can be optimized by use of sclerosant, such as sodium tetradecyl sulfate (STS) foam or ethanol to permanently occlude the internal spermatic vein. About 10 to 15% of patients have recurrent varicocele after embolization. This is usually due to collateral vessels, such as from the right spermatic vein or the splanchnic veins. Embolizing as low as possible, while preventing pampiniform phlebitis by externally compressing the external inguinal ring, and empiric bilateral embolization appear to have the best outcome for preventing recanalization. Complications of varicocele embolization are uncommon. They include pampiniform phlebitis and venous thromboembolism into the renal vein or pulmonary artery.

We define the histopathologic findings and review the clinical and radiologic characteristics of rapidly involuting congenital hemangioma (RICH). The features of RICH are compared to the equally uncommon noninvoluting congenital hemangioma (NICH) and common infantile hemangioma. RICH and NICH had many similarities, such as appearance, location, size, and sex distribution. The obvious differences in behavior served to differentiate RICH, NICH, and common infantile hemangioma. Magnetic resonance imaging (MRI) of the three tumors is quite similar, but some RICH also had areas of inhomogeneity and larger flow voids on MRI and arterial aneurysms on angiography. The histologic appearance of RICH differed from NICH and common infantile hemangioma, but some overlap was noted among the three lesions. RICH was composed of small-to-large lobules of capillaries with moderately plump endothelial cells and pericytes; the lobules were surrounded by abundant fibrous tissue. One-half of the specimens had a central involuting zone(s) characterized by lobular loss, fibrous tissue, and draining channels that were often large and abnormal. Ancillary features commonly found were hemosiderin, thrombosis, cyst formation, focal calcification, and extramedullary hematopoiesis. With one exception, endothelial cells in RICH (as in NICH) did not express glucose transporter-1 protein, as does common infantile hemangioma. One RICH exhibited 50% postnatal involution during the 1st year, stopped regressing, was resected at 18 months, and was histologically indistinguishable from NICH. In addition, several RICH, resected in early infancy, also had some histologic features suggestive of NICH. Furthermore, NICH removed early (2-4 years), showed some histologic findings of RICH or were indistinguishable from RICH. We conclude that RICH, NICH, and common infantile hemangioma have overlapping clinical and pathologic features. These observations support the hypothesis that these vascular tumors may be variations of a single entity ab initio. It is unknown whether the progenitor cell for these uncommon congenital vascular tumors is the same as for common infantile hemangioma.

Objective: The purpose of this study was to compare the safety and efficacy of oral cherry-flavored pentobarbital sodium (Nembutal) and oral chloral hydrate to sedate infants undergoing radiologic imaging., Subjects and Methods: We prospectively recorded data for all infants sedated with oral cherry-flavored pentobarbital sodium and oral chloral hydrate for imaging examinations between January 1997 and August 1999. The parameters recorded were each patient's age, weight, and American Society of Anesthesiologists classification; the time required to sedate; the total length of sedation time; the time required to discharge from the recovery room; and adverse events. The two-sample Student's t test and Fisher's exact test were used for statistical analysis., Results: Oral pentobarbital sodium was administered to 317 infants. These infants had a mean age +/- SD of 6.9 +/- 3.1 months and a mean weight of 7.8 +/- 4.8 kg; they received a median dose of 4 mg/kg of body weight. Oral chloral hydrate was administered to 358 infants. These infants had a mean age of 5.9 +/- 3.3 months and a mean weight of 7.3 +/- 4.9 kg; they received a median dose of 50 mg/kg of body weight. The mean time required to sedate was 19 +/- 14 min for infants receiving oral pentobarbital sodium and 16 +/- 11 min for infants receiving oral chloral hydrate (p = 0.02); the mean time required to discharge was 100 +/- 35 min for infants in the oral pentobarbital sodium group and 103 +/- 36 min for infants in the oral chloral hydrate group (p = 0.31); the mean length of sedation was 81 +/- 34 min for the oral pentobarbital sodium group and 86 +/- 36 min for the oral chloral hydrate group (p = 0.07); and median American Society of Anesthesiologists classification for both groups was P1. Oral pentobarbital sodium was inadequate for sedation in one patient (0.3%) and chloral hydrate was inadequate for sedation in another (0.3%) (p = 1.00). Adverse events were recorded for five patients (1.6%) in the oral pentobarbital sodium group and for six patients (1.7%) in the chloral hydrate group (p = 0.99)., Conclusion: Oral pentobarbital sodium is as safe and efficacious as oral chloral hydrate for sedating infants.

Vascular anomalies involving both intra- and extra-cranial structures are more common than previously thought. It is important to evaluate the brain and its coverings carefully when imaging cervicofacial vascular malformations. Scientific knowledge regarding developmental mechanisms responsible for blood vessel formation is increasing rapidly and, hopefully, will contribute to better understanding of these clinical and imaging "patterns."

Aim: To describe the imaging findings (MR imaging and angiography) of high-flow vascular anomalies of the tongue, hemangiomas and arteriovenous malformations (AVMs), with emphasis on the discrepant imaging findings in lingual AVMs., Materials and Methods: Retrospective review of clinical records, histologic reports and imaging studies of five consecutive patients with high-flow lingual vascular anomalies., Results: One patient had hemangioma (aged 1 month) and four patients had AVMs (aged 15 months, 6, 24, and 33 years). Diagnosis was made on the basis of histology in four lesions and was based on typical clinical history in one lesion. MR imaging and angiographic findings of the hemangioma were typical, but similar findings of focal hyperintense mass on T2-weighted images and angiographic stain were seen in three AVMs (patients aged 15 months, 6 and 33 years). On angiography, there was no nidus or direct arteriovenous (AV) shunting in one AVM (patient aged 15 months). The fourth AVM had typical MR imaging and angiographic findings., Conclusion: The imaging findings in lingual AVMs can be atypical or inconclusive and can mimic hemangiomas, especially in the young patient. Since treatment depends on accurate diagnosis, biopsy may be necessary for lesions with inconclusive imaging findings.

Rapidly involuting congenital hemangioma (RICH) is a recently recognized entity in which the vascular tumor is fully developed at birth and undergoes rapid involution. Angiographic findings in two infants with congenital hemangioma are reported and compared with a more common postnatal infantile hemangioma and a congenital infantile fibrosarcoma. Congenital hemangiomas differed from infantile hemangiomas angiographically by inhomogeneous parenchymal staining, large and irregular feeding arteries in disorganized patterns, arterial aneurysms, direct arteriovenous shunts, and intravascular thrombi. Both infants had clinical evidence of a high-output cardiac failure and intralesional bleeding. This congenital high-flow vascular tumor is difficult to distinguish angiographically from arteriovenous malformation and congenital infantile fibrosarcoma.

Intramuscular venous malformations are often mistaken for tumors because of a similar presentation and improper nomenclature. This is a review of 176 patients with venous malformations localized to skeletal muscle compiled from the Vascular Anomalies Center at Children's Hospital from 1980 through 1999. The female-to-male ratio was 2:1. Two-thirds of skeletal muscle venous malformations were noted at birth; the remainder manifested in childhood and adolescence. Venous malformations occurred in every muscle group, most often in the head and neck and extremities. Pain and swelling were the usual presenting complaints. Skeletal problems, such as fracture, deformation, or growth abnormalities, were rare. Hormonal exacerbation and intralesional bleeding were infrequent. Magnetic resonance imaging showed the lesions to be isointense to surrounding muscle on T1-weighted sequences and hyperintense on T2-weighted images. Characteristic tubular or serpentine components were oriented along the muscular long axis. Thrombi were hyperintense on T1-weighted and hypointense on T2-weighted sequences; phleboliths were seen as signal voids on all sequences. Gross examination of resected specimens revealed multicolored tissue with dilated vascular channels, frequently containing phleboliths. Light microscopy showed aggregates of primarily medium-sized, thin-walled vascular channels with flat endothelium and variable smooth muscle, most closely resembling dysplastic veins. Three lesions had a different histologic appearance consisting predominantly of small vessels with capillary structure and proliferative activity admixed with large feeding and draining vessels, similar to a lesion called intramuscular capillary hemangioma in the literature. The endothelium in these three lesions was negative for glucose transporter-1 by immunostaining. Eight percent of the patients, who had minor or no symptoms, were not treated. Twenty-four percent of the patients were managed conservatively (with aspirin and compressive garments); for 17 of these patients (10 percent of 176), noninvasive therapy was not successful, and they proceeded to sclerotherapy, excision, or both. A total of 31 percent of the patients had sclerotherapy, 20 percent had excision, and 27 percent had combined sclerotherapy and excision. Sclerotherapy was used for diffuse lesions, except for those with multiple intralesional thromboses, neurologic impairment, or compressive signs and symptoms. Resection was preferred for venous malformations well localized to a single muscle or muscle group, particularly if the muscles are expendable. Therapeutic outcomes were recorded in the charts or obtained by telephone interview in 122 of the patients (69 percent). Of these, compression garment and aspirin, resection, sclerotherapy, or combined excision and sclerotherapy improved symptoms in 121 patients (92 percent); no change was noted in 10 patients (8 percent). Only one patient was worse (self-reported) after intervention.

Purpose: To establish a protocol for credentialed pediatric radiology nurses, with radiologist supervision, to administer ketamine to induce sedation and analgesia during interventional radiologic procedures., Materials and Methods: This study was conducted in two phases. The goal of the first phase was to develop a sedation protocol to replace that of using general anesthesia for specified pediatric interventional procedures. Ketamine was administered intravenously (with intermittent bolus or continuous infusion) or intramuscularly. Sedation induction times, adverse events, doses, and sedation and recovery durations were recorded. In phase 2, the results of phase 1 were reviewed and a formal ketamine protocol was developed., Results: Neither sedation failures nor substantial adverse events occurred in phase 1. Mean duration of all sedations was 52 minutes, and median recovery room time was 0 minutes. In phase 2, the results of phase 1 were reviewed and a sedation protocol was proposed to a hierarchy of hospital committees before final approval from the medical staff executive committee. Subsequently, standard order forms for radiology nurse administration of ketamine with radiologist supervision were prepared for exclusive use by the pediatric interventional radiology department., Conclusion: Ketamine-induced sedation may be a safe and effective alternative to general anesthesia for some interventional radiologic procedures in pediatric patients. Collaboration between anesthesia and radiology departments is important for development of a safe and successful ketamine sedation program. To the authors' knowledge, this is the first report describing the intravenous infusion of ketamine for sedation in pediatric patients and the only report describing the establishment of a protocol for ketamine administration by credentialed radiology nurses with radiologist supervision., (Copyright RSNA, 2002)

Summary: We retrospectively evaluated 53 consecutive patients with cervicofacial venous malformation who had sclerotherapy. This review included a demographic analysis, MRI reexamination and tabulation of interventional therapeutic strategies. All patients whose MRI studies were included in this review demonstrated characteristic findings: space occupying lesion with hyperintense T2 signal abnormality, patchy contrast enhancement, and no flow signal on the gradient echo images.We concluded that a complete MRI work-up of these patients requires post-contrast scanning and gradient-echo imaging in addition to the standard T1 and T2 weighted spin echo imaging. The majority of patients had sporadic (non-familial) venous anomalies. Sinus pericranii (SP) was identified in six patients (11%) and blue rubber bleb nevus syndrome (BRBNS) was found in two patients (4%). MRI findings of sinus pericranii are discussed in detail. Although sodium tetradecyl and/or absolute ethanol are the most commonly used sclerosants, a wide variety of therapeutic strategies (depending on the nature of the abnormality) are also needed for these patients.

Knowledge of normal aortic dimensions is important in the management of children with aortic disease. So as to define such dimensions, we undertook a retrospective review of clinical data and aortic cineangiograms from 167 subjects without aortic disease having a mean age of 3.67 years, with a range from 0.01 to 14.95 years. Amongst the patients, 56 were without detectable cardiac lesions, 66 patients had mild pulmonary stenosis, 30 were seen with Kawasaki disease, and 15 with small interatrial defects within the oval fossa. Aortograms were available in all. No patient had any hemodynamic derangement that would have affected the aorta during intrauterine life or childhood. Systolic dimensions were measured in the ascending and descending aorta at the level of the carina, at the transverse aortic arch distal to the brachiocephalic, of the left common carotid artery at its origin, at the transverse aortic arch distal to the left common carotid artery, at the aortic isthmus, and of the aorta at the level of the diaphragm. A regression analysis model was used to establish the range of predicted normal values, with their confidence limits, standardizing the values to height as the biophysical parameter having the highest correlation to aortic dimensions. Normal ranges were established for all the levels of measurement. The data should prove useful in identifying abnormalities of the thoracic aorta during childhood, and when assessing the outcomes of interventions.

We present direct evidence for stable oligomers in vacuum-deposited thin films of zinc(II) bis(8-hydroxyquinoline) (Znq(2)). The tetramer [(Znq(2))(4)] is the energetically favored configuration in both the single crystal and the vacuum-deposited thin film. Oligomerization leads to distinct, symmetry-driven differences between the electronic states in Znq(2) and those in the archetypal organic electroluminescent molecule tris(8-hydroxyquinoline) aluminum (Alq(3)). In the case of the Znq(2) tetramer, symmetry leads to an extended network of overlapping pyridyl and phenolato moieties in the solid film. Analysis of the electronic structure of (Znq(2))(4) calculated by ab initio Hartree-Fock (HF) methods reveals a localization and energy shift of high-lying occupied and low-lying unoccupied states on symmetry related ligands located on opposite sides of the supramolecular structure resulting in a dipole moment for (Znq(2))(4) tetramer close to zero. The optimal pi-overlap pathways, altered charge distributions, and extended electronic states of tetrameric Znq(2) may be expected to enable low operating voltage organic light-emitting devices (OLEDs) based on Znq(2). We present preliminary evidence that the operating voltage of (Znq(2))(4)-based OLEDs is indeed lower than that of identical devices made with Alq(3). Strategic substitution of 8-hydroxyquinoline ligands and control of the structural symmetry of the corresponding metal chelates may offer a route to high efficiency and low operating voltage small molecule OLEDs.

More than half of the patients with vascular anomalies referred to the Vascular Anomalies Clinic at Children's Hospital, Boston, have been misdiagnosed. A major consequence of misdiagnosis is inappropriate treatment, including deferral of necessary treatment and inappropriate use of pharmacotherapy, radiation, surgery, and embolotherapy. Hemangiomas and vascular malformations are distinct categories with completely different biologic and clinical behavior, therapeutic requirements, and imaging features. This article reviews the biologic classification of vascular anomalies and corresponding MR imaging features, and presents a simplified guide to diagnosis.

Background: An increase in the number of patients undergoing sedation for imaging procedures has led to many changes in practice over the past 10 years., Objective: The purpose of this study was to compare and evaluate sedation practice changes in a pediatric radiology department during the last 5 years., Materials and Methods: The radiology computer database and corresponding minutes of the Radiology Sedation Committee were reviewed to identify changes in sedation policy. Data from three blocks of time were analyzed to determine time to sedation, time to discharge, drug frequency, rates of adverse events, sedation failure, and paradoxical reaction., Results: Specific practice changes undertaken over the 5-year period include: (1) increased speed of administration of IV pentobarbital, (2) alternating pentobarbital and fentanyl, (3) presedation with midazolam, and (4) administering oral pentobarbital to children under and (5) over 12 months of age. Based on data analysis, changes 1 and 4 were incorporated into the sedation policy, while changes 2, 3, and 5 were abandoned. Comparison of data from the three time segments revealed improvement in the time to sedation, sedation failure, adverse event, and paradoxical reaction rates., Conclusion: There is improvement in all aspects of patient outcomes with sedation, as a result of several changes in sedation practice.

Purpose: To review the angiograms in patients with hepatic hemangiomas referred to two North American children's hospitals to determine the variability in angiographic findings and to propose a classification system that is based on these findings., Materials and Methods: Angiograms obtained in 15 infants with a diagnosis of hepatic hemangioma who were examined at or referred to two tertiary pediatric hospitals in North America from 1981 through 2000 were reviewed. The angiographic findings were then used to classify hemangiomas into types on the basis of a number of features, including high-flow nodules, early filling of veins, and the type of direct shunt present. Clinical data, including age at presentation, presence of cardiac insufficiency, and treatment, were also recorded., Results: Lesions were classified into five types on the basis of angiographic findings. In three of 15 patients, angiograms demonstrated the classic appearance of hepatic hemangiomas, with early filling of abnormal vascular channels, stagnation of contrast material, and no evidence of a direct shunt (type 1). In four patients, images showed high-flow nodules without direct shunts (type 2). In eight patients, direct shunts were demonstrated: arteriovenous shunts (type 3) in one, portovenous shunts (type 4) in three, and both arteriovenous and portovenous shunts (type 5) in four., Conclusion: Hepatic hemangioma in infants is a heterogeneous lesion with variable angioarchitecture and a spectrum of angiographic findings.

Background/purpose: Vascular anomalies are diagnosed prenatally with increasing frequency. The authors reviewed a group of children treated at their center who had an abnormal prenatal diagnosis to determine (1) fetal age at which the vascular anomaly was detected, (2) general diagnostic accuracy, and (3) impact on ante- and postnatal care. Their findings are compared with reported cases and series. The authors clarify appropriate terminology and underscore the need for interdisciplinary participation of specialists in the field of vascular anomalies., Methods: Patients referred during prenatal life and children with a history of abnormal antenatal findings seen at our vascular anomalies center during a 1-year period (September 1999 through August 2000) were included in this study. The fetal age at diagnosis, pre- and postnatal diagnoses, antenatal course, and neonatal outcome were obtained from the parents, through chart reviews, and through telephone interviews with the treating obstetricians., Results: Twenty-nine patients with vascular anomalies were identified: 17 had a correct prenatal diagnosis, and 12 had an incorrect diagnosis, an overall diagnostic accuracy of 59%. Capillary-lymphatic-venous malformations (CLVM) most often were correctly diagnosed (67%), followed by lymphatic malformation (LM, 62%) and hemangioma (59%). In the infants who received correct diagnoses in utero, there were no fetal deaths and there was no neonatal morbidity. Maternal steroids were administered for a fetus with an intrahepatic hemangioma and deteriorating cardiac function, with subsequent stabilization and successful delivery of a healthy neonate. Among infants with incorrect diagnoses, there was 1 postnatal death, 1 case of erroneous gender assignment, 1 case of unnecessary fetal surgical intervention, 1 unnecessary neonatal laparotomy, and 1 delay in diagnosis of a malignancy. Cesarean section was done for 65% of correctly diagnosed cases, (including 2 ex utero intrapartum [Exit] procedures) and for 33% of incorrectly diagnosed cases. Most diagnoses were made during the mid- to late second trimester and third trimester; only 4 cases (14%) were detected before 20 weeks., Conclusions: In this series, accurate diagnosis optimized antenatal care by providing an opportunity for planning deliveries, for pharmacologic fetal intervention in 1 case, and for appropriate parental counselling. Inaccurate diagnosis was associated with significantly increased morbidity and mortality. Finally, the intrauterine diagnosis of LM should be distinguished from posterior nuchal translucency, an obstetric term applied to fetal lymphatic abnormalities detected in the first and second trimesters that do not manifest as postnatal LM., (Copyright 2002 by W.B. Saunders Company.)

Lymphatic malformations can occur anywhere in the head and neck, and when they do so in the oral cavity, they can present a potential hazard to the airway. We describe a 4-year-old girl with a giant lymphatic malformation of the tongue and neck. This report illustrates the particular difficulties that may be encountered in cases involving giant lymphatic malformations of the cervicofacial region in the pediatric population. An overview of the etiology, diagnosis, histology, and options for the management of such lesions is outlined.

Objective: The purpose of our study was to examine the coagulation status in patients with vascular anomalies who had undergone sclerotherapy or embolization., Subjects and Methods: Ours was a prospective pilot study of 29 patients who had undergone sclerotherapy or embolization of large vascular anomalies. Fibrinogen, platelet, and d-dimer levels and prothrombin time were obtained before, immediately after, and on the day after the procedure., Results: Five patients with venous malformations had positive d-dimer levels before the procedure. A subgroup analysis revealed a relationship between the type of agent used and the change in coagulation status. Specifically, a positive relationship was found between the use of dehydrated alcohol or sodium tetradecyl sulfate and a disruption in coagulation profiles as evidenced by a decrease in platelets and fibrinogen, an increase in prothrombin time, and a conversion from negative to positive d-dimers. In contrast, sclerotherapy or embolization with cyanoacrylic, polyvinyl alcohol foam particles, or platinum microcoils was not associated with coagulation disturbances., Conclusion: The coagulation disturbances that occur in response to dehydrated alcohol or sodium tetradecyl sulfate sclerotherapy or embolization could compromise the patient's clotting ability. Patients who receive dehydrated alcohol or sodium tetradecyl sulfate during a preoperative sclerotherapy or embolization may experience coagulation disturbances that could increase the risk of bleeding, thrombosis, or hematoma. This patient population may benefit from the use of glue, foam, or coils as a substitute for dehydrated alcohol or sodium tetradecyl sulfate.

A 13-year-old girl who recently developed hypertension was diagnosed to have an occluded right renal branch artery and was treated successfully with percutaneous transluminal angioplasty (PTA). To our knowledge, PTA has not been reported as a treatment for totally occluded renal branch arteries, and there is no data available regarding the success rate and possible complications.

The typical vascular anomalies (tumors and vascular malformations) that involve the liver in infants and children are summarized. Many of these lesions are complex and require multiple imaging modalities, often including angiography, for precise diagnosis.

Congenital anomalies of the thoracic duct are rare, poorly characterized, and difficult to manage. The spectrum of pathophysiologic perturbations, presenting symptoms, radiographic findings, and interventions performed in 4 patients are shown. Accurate anatomic delineation of the malformation was only possible by direct injection contrast lymphangiography. Therapies tailored to address the anatomic aberrations included intralesional sclerotherapy, surgical excision and ligation, lymphovenous anastomosis, and omental interposition to interrupt dysfunctional collateral lymphatics to the lung. Accurate anatomic diagnosis of central lymphatic channel anomalies by contrast lymphangiography facilitates an individualized multidisciplinary approach to repair., (Copyright 2001 by W.B. Saunders Company.)

Objective: This study was designed to evaluate safety, efficacy, and success of adding IV midazolam to an established IV pentobarbital protocol for pediatric sedation for radiologic imaging. Outcomes included sedation and discharge times as well as adverse events, Subjects and Methods: This prospective study compared two different sedation protocols developed by the radiology sedation committee and approved by the hospital sedation committee at our institution. Patients in the pentobarbital group received IV pentobarbital alone, and patients in the pentobarbital--midazolam group received a combination of IV pentobarbital and midazolam. A total of 1070 infants and children were enrolled, and sedation data were entered into a computer database and reviewed at bimonthly radiology sedation committee meetings for safety, efficacy, efficiency, failed sedations, and adverse outcomes., Results: Mean age distribution, sex, American Society of Anesthesiologists physical status classification, fasting status, weight, and types of examinations were similarly distributed between the two study groups. Analysis of variance indicated longer times were required to sedate and to discharge patients who had received pentobarbital--midazolam (p < 0.001 for both times), even after adjusting for differences in the patients' ages and weights. The pentobarbital--midazolam group required more time to be successfully sedated and more time to discharge from the recovery room. The rates of adverse events and failed sedations were similar for both groups., Conclusion: Midazolam does not have a beneficial effect on pentobarbital sedation and has no effect on the rate of adverse events. The prolonged time needed both to sedate and to discharge (timed from the initial dose of sedation) pediatric patients who have received midazolam should discourage physicians from combining it with pentobarbital for pediatric sedation.

We relate the chemical structure of a series of methyl (Me) substituted group III metal tris(8-quinolinolato) chelates (nMeq(3)M: n = 0, 3, 4, 5; M = Al(3+), Ga(3+)) to their photoluminescence (PL), electroluminescence, and thermal properties. Methylation of the 8-quinolinol ligand at the 3 or 4 position (pyridyl ring) results in a factor of 1.4 and 3.0 enhancement of PL quantum efficiency (phi(PL)), respectively, whereas methylation at the 5 position (phenoxide ring) results in a factor of approximately 3.0 decrease in phi(PL) relative to the unsubstituted analogue. Electroluminescent quantum efficiencies of undoped organic light-emitting devices using the aluminum tris(8-quinolinolato) chelates are 1, 0.45, 1.4, and 0.80% for unsubstituted 5-, 4-, and 3-methyl-8-quinolinol ligands, respectively. Devices made with the latter two ligands have a higher operating voltage to generate the same current density. Similar trends were observed for methylation of gallium tris(8-quinolinolato) chelates. We relate these results to the thermal properties of the compounds measured by simultaneous differential scanning calorimetry and thermal gravimetric analysis. The C-4 methylated derivatives exhibit approximately 60 degrees C lower crystalline melting points than all other derivatives, indicating the weakest cohesive forces between molecules. Unlike Alq(3), both the C-4 and C-5 methylated derivatives show no recrystallization of the glassy state below 500 degrees C and exhibit approximately 20-25 degrees C higher glass transition temperatures. We infer that methylation of the 8-quinolinol ligand reduces intermolecular interactions and consequently impedes charge transport through the film.

Objectives: To define the morphologic abnormalities in patients presenting with diffuse pure venous malformations (VM) of the upper extremity., Subjects and Methods: A retrospective review of MRI and venography was performed on five patients, aged 6 months to 20 years, with extensive VM of the upper limbs. Abnormalities of major conducting veins were categorized as varicosities, stenoses, and asymmetrical pouches; anomalous venous spaces were classified into confluent lakes, interconnecting channels and spongelike plexiform networks. MRI and venographic data were reviewed separately and then simultaneously in order to establish correlation between types, location, and extent of lesions., Results: In all patients, the percentage of replacement of normal tissues by VM was shown by MRI to be significantly higher in the distal limb than in the proximal limb. Involvement of multiple tissue layers was seen in all cases, including, with a decreasing rate, muscles, tendons, interosseous membrane of the forearm, and bone. Venography showed superficial varicosities, frequently associated with stenoses and assymetric pouches in all patients. Interconnecting channels and venous lakes were noted in half of the segments, typically in muscle and other deep locations, and subcutaneous spongelike lesions were seen in two patients. MRI provided a more accurate evaluation of tissue extent. Venograms better demonstrated morphological details and provided more information about the venous drainage. Direct comparison of MR images with venograms helped to identify and characterize venous lesions on cross-sectional MR data., Conclusion: Diffuse VM of the upper extremity are most extensive distally, and all tissues layers can be involved, each with a characteristic morphologic appearance. The morphology of different components of the VM is related to the nature of the surrounding tissue.

The authors studied a rare, congenital, cutaneous vascular anomaly that grows proportionately with the child and does not regress. A total of 53 patients were compiled from three vascular anomaly centers. These patients' lesions were analyzed for presentation, physical findings, radiologic and histopathologic characteristics, natural history, and outcome after resection. The lesions occurred slightly more often in male patients, always appeared alone, and were located (in order of frequency) in the head/neck region, extremities, and trunk. They were round-to-ovoid in shape, were plaque-like or bossed, occurred in variable shades of pink to purple, and had an average diameter of 5 cm. The overlying skin was frequently punctuated by coarse telangiectasia, often with central or peripheral pallor. The lesions were warm on palpation; fast-flow was further documented by Doppler ultrasonography. Magnetic resonance imaging and angiographic findings were similar to those of common hemangioma of infancy. All lesions were easily excised without recurrence.Histologic examination revealed lobular collections of small, thin-walled vessels with a large, often stellate, central vessel. Interlobular areas contained predominantly dilated, often dysplastic veins; arteries were also increased in number. Small arteries were observed "shunting" directly into lobular vessels or into abnormal extralobular veins. "Hobnailed" endothelial cells lined the small intralobular vessels. Mast cells were increased. Tests for glucose transporter-1, a recently reported reliable marker for common hemangioma of infancy, were negative in all 26 specimens examined. In conclusion, the authors think these clinicopathologic and radiologic features define a rare vascular lesion for which the term "noninvoluting congenital hemangioma" is proposed. These lesions of intrauterine onset may be a variant of common hemangioma of infancy or another hemangiomatous entity with persistent fast-flow.

The synthesis and photophysical study of a family of cyclometalated iridium(III) complexes are reported. The iridium complexes have two cyclometalated (C(**)N) ligands and a single monoanionic, bidentate ancillary ligand (LX), i.e., C(**)N2Ir(LX). The C(**)N ligands can be any of a wide variety of organometallic ligands. The LX ligands used for this study were all beta-diketonates, with the major emphasis placed on acetylacetonate (acac) complexes. The majority of the C(**)N2Ir(acac) complexes phosphoresce with high quantum efficiencies (solution quantum yields, 0.1-0.6), and microsecond lifetimes (e.g., 1-14 micros). The strongly allowed phosphorescence in these complexes is the result of significant spin-orbit coupling of the Ir center. The lowest energy (emissive) excited state in these C(**)N2Ir(acac) complexes is a mixture of (3)MLCT and (3)(pi-pi) states. By choosing the appropriate C(**)N ligand, C(**)N2Ir(acac) complexes can be prepared which emit in any color from green to red. Simple, systematic changes in the C(**)N ligands, which lead to bathochromic shifts of the free ligands, lead to similar bathochromic shifts in the Ir complexes of the same ligands, consistent with "C(**)N2Ir"-centered emission. Three of the C(**)N2Ir(acac) complexes were used as dopants for organic light emitting diodes (OLEDs). The three Ir complexes, i.e., bis(2-phenylpyridinato-N,C2')iridium(acetylacetonate) [ppy2Ir(acac)], bis(2-phenyl benzothiozolato-N,C2')iridium(acetylacetonate) [bt2Ir(acac)], and bis(2-(2'-benzothienyl)pyridinato-N,C3')iridium(acetylacetonate) [btp2Ir(acac)], were doped into the emissive region of multilayer, vapor-deposited OLEDs. The ppy2Ir(acac)-, bt2Ir(acac)-, and btp2Ir(acac)-based OLEDs give green, yellow, and red electroluminescence, respectively, with very similar current-voltage characteristics. The OLEDs give high external quantum efficiencies, ranging from 6 to 12.3%, with the ppy2Ir(acac) giving the highest efficiency (12.3%, 38 lm/W, >50 Cd/A). The btp2Ir(acac)-based device gives saturated red emission with a quantum efficiency of 6.5% and a luminance efficiency of 2.2 lm/W. These C(**)N2Ir(acac)-doped OLEDs show some of the highest efficiencies reported for organic light emitting diodes. The high efficiencies result from efficient trapping and radiative relaxation of the singlet and triplet excitons formed in the electroluminescent process.